Extended duplex fault tolerant system with integrated control flow checking

ISBN: 0306435314Proposes an extended duplex architecture allowing one to reduce the general costs of onboard fault tolerant equipments and ensuring acceptable availability. This architecture is an intermediate solution between TMR and classical duplex. Furthermore, the problem of the workload is addressed and the basic component is the new MC88100 RISC microprocessor. One subsystem is made up of only one MC88100; the other one is based on the same microprocessor coupled with a `checker microprocessor' as offered in the MC88100 features. Instruction and data memories are only duplicated, as in a normal duplex architecture. Dedicated VLSI circuitry and comparators are introduced to ensure the concurrent checking of the two subsystems. The system errors are detected on line and the faulty subsystem can be localized. This allows a rapid recovery of the system, in such a way that continuity is maintained